Railway signaling system



Sept. 8, 1936, D. J. MQQARTHYI 2,053,775

RAILWAY SIGNALING SYSTEM Filed May 23, 1934 v I 4 E l9- INVENTOR Patented I Sept. 8, 1936 UNITED STATES PATENT OFFICE RAIIAWAY SIGNALING S YSTEM Application May 23,. 1934, Serial No. 727,025

7 Claims.

'1 r The present invention relates in general to railway signaling and more particularly to automatic railway crossing protection. 7

The. main object of. the presentinvention is to provide reliable and inexpensive means whereby the speed of a train between two given points determines whether or not a. signal is to be operated.

Another object of the present invention is the provision of means: controlled by a train reaching a predetermined point for operating signaling not a signal is to be operated and may be used for' bothrailroadgrade crossings and highway crossings or at other points where it is desired to limit the speed of trains. In the present embodiment of the invention the circuits are so arranged that unless the speed of the trainbetween the two given points is limited to the proper speed or less 30l,the signal at a railroad intersection will be automatically set against the train. In case, however, the train passes between said two given points at the properly reduced speed from a safety standpoint, the crossing signal indicates clear and per- 35 mits' the train to enter the intersection. Therefore, in order to get a clear indication from the signal, the speed of the train must be within certain limits while passing between two given points.

40: In a co-pending application executed by me of even date herewith, Serial N0.. 727,026,. filed May 23, 1934, I have shown the fundamental principles of the present invention used for controlling the operation of a highway crossing signal 45- which is used to warn highway trafiic of an appreaching train. In the. co-pending application the highway signal. is operated by the. approaching train from one given point in case the speed of the train exceeds a predetermined speed and is 50 operated by the train from another given point in case the speed of the train is less than said predetermined speed so that the operating time of the signal, or the warning time for the highway trafiio, before the train actually reaches the highway crossing, is the same for bothfast and slowly approaching trains, The co pending application contains the narrow claims directed to the specific: disclosures therein, while the instant application contains the broader claims directed to the operation of. signals dependent upon the speed of the train.

Referring now to the drawing, T represents the. two rails of a railroad track on which trains approach a railroad grade intersection or crossing (not shown) in the direction indicated by the arrow. 2 indicates a signal placed a predetermined distance from the crossing, and 3 indicates the signal located at the intersection or crossing. Along the inside of one of the rails are placed contactors for controlling circuit controlling contacts 4),, 5,. 6, and 1 These contactors. may be substantially of the same design and operation as disclosed in the application of H. F.. Obergfell and G. W.. Eickenberg, Serial. No. 639,-

558, filed October 26, 1932,. wherein the plunger is.

operated by the train wheels to cause: the operation of the circuit controlling: contacts in the associated: housing. The corresponding circuit controlling contacts in the present drawing are indieaten at 4,. 5, .6, and I wherein such contacts are 2 5- operated by the associated plungers. represented by small circles placed on the. inside of the lower rail. Contacts 4 are placed along the track a short distance: from signal 2, while the contacts 5 are placed along the track a predetermined dis- 3o tance from contacts 4. The contacts. 4 and 5 are. separated a definite distance dependent upon the operating time of. the slow-acting device in this case a chain of slow-releasing relays l0 and I1, so that it may be determined when the speed of a trainpassing between contacts 4 and 5 exceeds a predetermined speed. Contacts 6 and I are placed close tothe crossing in order to reset the signaling and timing means when the train is proceeding across the: crossing. The. contactor contacts control circuits of a number of relays, two of which are of the slow-releasingtype having copper slugs on their armature ends, as indicated by the cross-hatched sections thereof. 9, l1, and 21 designate batteries for controlling the operation of the relays and crossing signal 3. The relays and signals are shown in their normal. condition wherein. relays: 8, till, i2, 24, and 25 are normally energized, the signal 2 is set. at caution, and the crossing signal 3 is set at clear. 3 is maintained in clear position over a circuit including armature 26 and battery 21. Relay 25 is held energized over a circuit including armature 2 3 and battery l 'l Relay 24 is maintained energized over the following stick circuit: From.

Signal one pole of battery I I, conductor 22, winding of relay 24, conductor 30, stick armature 2I, conductors 26 and I9, contacts 5, and conductor I8 to the other pole of battery I'I. Relay 8 is maintained energized over the following stick circuit: From one pole of battery 9, contacts 4, conductor 3I, winding of relay 8, conductor 32, and lower stick armature of relay 8 to the other pole of battery 9. Relay I is held energized over a circuit including armature II of relay 8 and battery 9. Relay I2 is held energized over a circuit including armature I3 of relay Ii] and battery 9. If desired, additional slow-releasing relays may be added in this chain circuit to increase the release time before the last of the slow-releasing relays closes the circuit for relay I5 as a result of the deenergization of relay 8. The operation is as follows: When a train approaches caution signal 2 in the direction indicated by the arrow, the engineer reduces the speed in accordance therewith. Shortly after passing the caution signal 2 contacts 4 are operated by the wheels of the train, thereby opening the previously traced stick circuit for relay 8, whereupon relay 8 deenergizes. At its lower armature relay 8 opens a further point in its stick circuit to prevent its reenergization when contacts 4 close and at armature H opens the circuit of the first slowreleasing relay IE. After aninterval slow-releasing relay I 5 deenergizes and at armature I 3 opens the circuit to the next slow-releasing relay in the chain, which in this case is the last relay in the chain or relay I2. After an interval, dependent upon its slow-releasing characteristics, slowreleasing relay I2 deenergizes and at armature I4 completes a circuit for energizing relay I5. As previously stated, by the addition of more slowreleasing relays in the chain circuit the energize.- tion of relay I5 may be delayed in accordance therewith. The circuit for energizing relay I5 may be traced as follows: From one pole of battery 9, winding of relay i5, armature I4, to the other pole of battery 9. At armature I6 relay I5 closes a shunt circuit around contacts 5.

The operation from this point on is different dependent upon whether the speed of the train exceeds a predetermined speed or not. That is, the operation is different dependent upon whether contacts 5 are operated by the train before relay I5 closes the shunt circuit around contacts 5 or dependent upon whether thecontacts 5 are operated by the train after relay I5 closes the shunt circuit around contacts 5. Assuming first that relay I5 at armature I6 closes the shunt circuit around contacts 5 before the train operates contacts 5, then the operation of contacts 5 by the train is without effect since the stick circuit for signal control relay 24 now includes armature I6. Under this condition relays 24 and 25 are maintained energized and the crossing signal 3 is maintained at clear or proceed position to indicate that the train may proceed, it being understood that signal 3 will indicate clear only in case the track is in clear condition. As the train proceeds past signal 3 contacts 6 and I are closed. The closure of contacts 6 is without effect at this time because the signal 3 did not change but the closure of contacts I completes a circuit for resetting or reenergizing relay 8 as follows: From one pole of battery 9 by way of conductor 35, conductor 34, contacts I, conductor 33, conductor 32, winding of relay 8, conductor 3| and contacts 4 to the other pole of battery 9. Relay 8 energizes over the above-traced circuit and at its lower armature completes its previously traced stick circuit. At armature II relay 8, upon energizing, completes the circuit for energizing relay Ill. Relay IO, upon energizing, at armature I3 completes the circuit for energizing the next, in this case the last, relay or relay I2 in the chain circuit. At armature I4 relay I2 opens the circuit to relay I5 which thereupon deenergizes to remove the shunt circuit from around contacts 5 by opening contacts I6. The relays 8, I0, I2, and I5 are now reset to their normal positions in readiness for the next approaching train.

It will now be assumed that the engineer on the approaching train ignores the caution signal 2 and does not properly reduce the speed of the train. Relays 8, I0, I2, and I5 operate in the same manner as previously described in response 'to the train operating contacts 4. In this case,

however, the speed of the train is such that contacts 5 are operated by the train before relay I5 is operated and contacts I6 are closed. Since contacts 5 are opened before armature I6 is operated, the stick circuit of signal control relay 24 is opened with the result that such relay deenergizes. At armature 2I relay 24 opens a further point in its stick circuit to prevent its reenergization in response to the intermittent operation of contact 5 by the train passing thereover. At armature 23 relay 24 opens the circuit of signal relay 25, whereupon the latter relay deenergizes. At armature 26 relay 25 opens the circuit to signal 3, whereupon signal 3 is operated to the stop or danger condition in the well-known manner. From the foregoing, it will be seen that if the speed of a train is not reduced to the proper speed, the crossing signal 3 is set against the train regardless of track conditions. The crossing signals 3 may be so arranged that the same is held at danger until released by a dispatcher.

Relays 8, I0, I2, and I5 are reset in the manner previously described in response to the train closing contacts I. In response to the closure of contacts 6 as a result of the train passing signal 3 the following circuit is completed for energizing relay 24: From one pole of battery I'I, conductor 22, winding of relay 24, conductor 28, contacts 6 now closed, conductor 29, contacts 5 now closed, and conductor I8 to the other pole of battery Il. At armature 2I relay 24 completes its previously traced stick circuit and at armature 23 completes the circuit for energizing relay 25. At armature 26 relay 25 again completes the circuit for crossing signal 3, whereupon signal 3 is operated to clear or proceed position in the well-known manner. All of the apparatus has now been reset in readiness for the next train.

From the foregoing it will be seen that a, reliable and inexpensive arrangement has been provided for checking an engineman as to his observance of the rule regarding reduced speed when approaching speed restricted zones without installing expensive train stop or train control equipment.

Another precautionary measure has been taken by having the circuit operate on what is known as a closed circuit so that any failure of battery 9, will cause signal 3 to be set at danger regardless of the speed of the train. In case battery 9 fails for some reason, then relay I5 cannot energize to place a shunt circuit around contacts 5 as would be the case on battery failure if contacts I4 instead of contacts I6 closed such shunt circuit. Therefore, in case of failure of battery 9, the shunt circuit around contacts I5 is not completed with the result that the signal 3 is set against the train regardless of its speed in response to the operation of contacts 5.

It will be understood that while only one track with traific in one direction has been illustrated, a similar arrangement is provided for a second track having traffic in the opposite direction. Also the intersecting tracks will be provided with similar arrangements, if desired.

Having described the invention and'what is considered new and is desired to have protected by Letters Patent is set forth in the following claim.

What is claimed is.

1. In combination with a railroad track, signaling means located at a predetermined point along said track for governing the right of way over a grade crossing, said signaling means having proceed and stop positions and normally set in its proceed position, a plurality of track-side contactors mechanically operable by the wheels of trains approaching'said predetermined point, circuit controlling contacts mechanically controlled by said contactors when operated, the first one of said contactors to be operated by the approaching train being placed at considerable distance from said predetermined point, the second one of said contactors to be operated by the approaching train being placed at a definite distance from said first contactor, means controlled by the operation of the contacts in the operated first and second contactors for operating said signaling means from its proceed position to its stop position only in case the train travels between said first and second contactors with a speed exceeding a predetermined speed, and means operated in case the speed of the train is less than a predetermined speed between said first and second contactors for maintaining said signaling means in its proceed position during the approach and while the train is passing over said crossing.

2. In combination with a railroad track, signaling means located at a predetermined point along said track for governing the right of way over a grade crossing, said signaling means having proceed and stop positions and normally set in its proceed position, a plurality of track-side contactors operable by trains approaching said predetermined point, circuit controlling contacts controlled by said contactors when operated, the first one of said contactors to be operated by the approaching train being placed at considerable distance from said predetermined point, the second one of said contactors to be operated by the approaching train being placed at a definite distance from said first contactor, slow-acting means controlled by the contacts of said first contactor and initiated in its operation in response to the operation of said first contactor, means for controlling the operation of said signaling means from its proceed position to its stop position, means for operating said last means in response to the operation of the second of said contactors only in case the complete operation of said slowacting means is incomplete at the time said second contactor is operated, and means controlled by said slow acting means in case the slow acting means is fully operated at the time the said second contactor is operated for maintaining said signaling means in its proceed position while the train is approaching and passing over the crossing.

3. In combination with a railroad track, signaling means located at a predetermined point along said track for governing the right of way over a grade crossing, said signaling means having proceed and stop positions and normally set in its proceed position, track-side equipment operable by trains approaching said predetermined point, said equipment located along said track at predetermined distances from said predetermined point, means controlled by the operation of said track-side equipment for operating said signaling means from its proceed position to its stop position only in case a train approaches said predetermined point with a speedexceeding a predetermined speed, and means operated in case the speed of the train is less than a predetermined speed for maintaining said signaling means in its proceed positionwhile the train is approaching and passing over said crossing.

In a railway signaling system, a plurality of contacts located at predetermined points along thetrack 'and operable in succession by an ap preaching train, a normally energized start relay, a stick circuit for said start relay, said stick circuit opened in response to an approaching train operating the encountered one of said contacts to release said start relay, a chain of normally energized slow-releasing relays initiated in their releasing operations in response to the operation of said start relay, a normally open shunt circuit around the second of said contacts, means responsive to the release of the last slow releasing relay in the chain for closing said shunt circuit around the said second contacts, a signal controlling relay, a stick circuit for said signal relay including the said second contacts, and means for opening the stick circuit of said signal relay in response to the approaching train operating the said second contacts, said signal relay maintained energized over said shunt circuit in case said shunt circuit is closed before the operation of said second contacts.

5. In a railway signaling system, a plurality of contacts l cated at predetermined points along the track and operable in succession by an approaching train, a normally energized start relay, a stick circuit for said start relay, said stick circuit opened in response to an approaching train operating the first encountered one of said contacts to release said start relay, a chain of normally energized slow-releasing relays initiated in their releasing operations in response to the operation of said start relay, a normally open shunt circuit around the second of said contacts, means responsive to the release of the last slow releasing .relay in the chain for closing said shunt circuit around the said second contacts, a signal controlling relay, a stick circuit for said signal relay including the said second contacts, means for opening the stick circuit of said signal relay in response, to the approaching train operating the said second contacts, said signal relay maintained energized over said shunt circuit in case said shunt circuit is closed before the operation of said second contacts, and means controlled by other of said contacts for reenergizing said start relay to complete its stick circuit and reset said chain of relays and for reenergizing said signal controlling relay to complete its stick circuit in case the same has been opened.

6. In a railway signaling system, a plurality of contacts located at predetermined points along the track and operable in succession by an approaching train, a signal normally held in proceed position, a normally energized signal controlling relay for controlling said signal, a stick circuit for said relay including the second of said contacts operated by the approaching train, slowreleasing means initiated in response to the approaching train operating the first encountered one of said contacts, means operated by said slowreleasing means when fully operated for shunting the said second contacts after a predetermined time to maintain said stick circuit and said relay energized only in case the said second contacts are operated after the shunt is closed, the operation of said second contacts opening said stick circuit to release said relay only in case said second contacts are operated before said shunt is closed, said signal maintained in its proceed position while the train is approaching and passing over said crossing in case said relay is maintained energized over the shunt stick circuit and said signal being operated from proceed to stop position in case said relay is released, and means controlled by others of said contacts when operated for reenergizing and resetting said slow-releasing means and said signal relay if released.

7. In a railway signaling system, a plurality of contacts located at predetermined points along the track and operable in succession by an approaching train, slow-acting means controlled by the first contacts encountered by an approaching train, means controlled by said slow-acting means for rendering the operation of the second train encountered contacts 'inefiective for signaling purposes after a predetermined time, signaling means located at a grade crossing normally set at proceed position and operated to stop in response to the operation of the said second contacts only in case the approaching train operates the said second contacts before said slow-acting means operates said last means, said signaling means being maintained in its proceed position while the train is approaching and passing over said crossing in case said last means is fully operated before the train operates said second contacts.

DANIEL J. MCCARTHY. 

